Introduction
Bitcoin is a peer-to-peer currency. Peer-to-peer means that no central authority issues new money or tracks transactions. These tasks are managed collectively by the network.
It was created in 2009 by Satoshi Nakamoto. It is also the name of the open source software designed in order to use this currency.

Bitcoin is one of the first implementations of a concept called cryptocurrency, which was first described in 1998 by Wei Dai on the cypherpunks mailing list. Building upon the notion that money is any object, or any sort of record, accepted as payment for goods and services and repayment of debts in a given country or socio-economic context, Bitcoin is designed around the idea of using cryptography to control the creation and transfer of money, rather than relying on central authorities.

The Bitcoin economy is in an early stage of development. Bitcoins are currently accepted in some cases for online services, work for hire, tangible goods, and charitable donations. The Free Software Foundation, Electronic Frontier Foundation and Singularity Institute accept Bitcoin donations. Traders exchange regular currency (including US dollars, Russian rubles, and Japanese yen) for bitcoins through exchange sites. Anyone can view the block-chain and observe transactions in real-time. Various services facilitate such monitoring.

How it works
Bitcoin uses public-key cryptography, peer-to-peer networking, and proof-of-work to process and verify payments. Bitcoins are sent (or signed over) from one address to another with each user potentially having many, many addresses. Each payment transaction is broadcast to the network and included in the blockchain so that the included bitcoins cannot be spent twice. After an hour or two, each transaction is locked in time by the massive amount of processing power that continues to extend the blockchain. Using these techniques, Bitcoin provides a fast and extremely reliable payment network that anyone can use.

Features
These are the basic features of any Bitcoin-like network.

Bitcoins can be transferred between arbitrary nodes on the network.

Transactions are irreversible.

Double spending is prevented by using a block chain.

Transactions are broadcasted within seconds and verified within 10 to 60 minutes.

Transactions can be received at any time regardless of whether your computer is turned on or off.